This invention pertains to a process for producing mechanical power by utilizing compressed humidified air and a fuel to produce hot combustion gas for expansion in a gas turbine. It pertains particularly to such a power producing process in which hot compressed air is humidified with heated water and the mixture further heated in a heat recovery unit provided upstream of a fuel combustor and hot gas turbine.
Processes for producing mechanical power by utilizing a gas turbine for expanding a pressurized hot combustion gas and recovering heat from turbine hot exhaust gas are well known. Some recent such processes provide for water saturation of compressed hot air before the humidified air is utilized for fuel combustion and expansion through a hot gas turbine, which results in requiring less excess air and improved thermal efficiency and lower power costs. Such processes for producing power utilizing humidified air supply to a fuel combustor and hot gas turbine are disclosed by U.S. Pat. Nos. 4,829,763 and 5,181,376 to Rao. U.S. Pat. No. 5,160,096 to Perkins et al discloses a gas turbine cycle in which compressed humidified air is used to cool the turbine stationary blading. Also, U.S. Pat. No. 5,201,796 to Glinski et al and U.S. Pat. No. 5,218,815 to Korenberg each disclose gas turbine power processes in which compressed air is humidified upstream of a fuel combustor to assist in supplying oxygen and controlling temperature of the combustion before the hot gas is expanded in the gas turbine. However, these known power producing processes are relatively complex and have various limitations, so that further improvements and simplification in such gas turbine power producing cycles utilizing pressurized humidified air supply to the fuel combustion step and gas turbine are desired.